Diamondbacks' Walker has torn UCL, Tommy John surgery likely

Taijuan Walker's 2018 season appears to have come to a sudden end.

The Arizona Diamondbacks announced Wednesday that the right-hander has a torn ulnar collateral ligament in his elbow and will likely need Tommy John surgery, which would serve to end his season.

Walker left Saturday's start against the Dodgers because of right forearm tightness, and was placed on the disabled list the following day. An MRI then revealed his damaged UCL, but it took a little more time to determine the extent of the injury.

The 25-year-old is in his second season with the Diamondbacks after beginning his career in Seattle. In three starts this year he posted a 3.46 ERA and struck out nine with five walks.

For his career, Walker owns a 31-31 record, 3.96 ERA, and 477 strikeouts in 527 1/3 innings pitched.

Matt Koch will now start in Walker's stead Friday against the San Diego Padres.